i am trying to make a shop script for my first person shoot game. i switch weapons buy deleting the old weapon and instantiating a new one from a prefab. the weapon is suppose to auto position it's self according to variables in it's script, those variables are used in the aim script attached to the camera witch is a parent of the gun.

the system works fine except that i get this error when i switch weapons

transform.localPosition assign attempt for 'vzr8(Clone)' is not valid. Input localPosition is { -45.218674, -0.350000, NaN }.
UnityEngine.Transform:set_localPosition(Vector3)
aim:Update() (at Assets/scripts/player/gun/aim.js:33)

can any one tell me what it means and how to fix it. btw here is my shop script

private var toggle : boolean = false;
private var player : Transform;
private var skin: GUIStyle;
private var bg: Texture;

var guns : Transform[];

function Start(){
    player = gameObject.FindWithTag("Player").transform;
    skin = gameObject.FindWithTag("Master").GetComponent("master_gameInterface").skin;
    bg = gameObject.FindWithTag("Master").GetComponent("master_gameInterface").bg;
}

function OnGUI() {
    var dist = Vector3.Distance(player.position, transform.position);

    myStyle = new GUIStyle();
    myStyle.normal.textColor = Color.cyan;
    myStyle.font = skin.font;

    if(dist<5){
       if(Input.GetKey(KeyCode.E)){
         master_gameInterface.pause = true;
         toggle = true;
       }
       if(toggle==false)
         GUI.Label(Rect(Screen.width/2,Screen.height/2,200,200), "Press E to enter Shop", myStyle);
    }

    if(master_gameInterface.toggle)
       toggle = false;

    if(toggle){
    GUILayout.BeginArea(Rect(Screen.width/2-100,Screen.height/2-200,200,400), bg);
    GUILayout.BeginVertical();
       for(var i=0;i<guns.Length;i++){
         if(GUILayout.Button(guns[i].GetComponent("gun").name, skin)){
          if(player.GetChild(2).GetChild(0))
              Destroy(player.GetChild(2).GetChild(0).gameObject);
          var me = Instantiate(guns[i], player.position, Quaternion.identity);
          me.parent = player.GetChild(2);
          me.localPosition = player.GetChild(2).position;
          player.GetChild(2).GetComponent("aim").gun = me;
         }
       }

       GUILayout.Label("\n");
       if(GUILayout.Button("Done", skin)){
         master_gameInterface.pause = false;
         toggle = false;
       }
    GUILayout.EndVertical();
    GUILayout.EndArea();
    }
}

function deleteGun(){
    for (var child : Transform in transform) {
        child.position += Vector3.up * 10.0;
    }
}

[Edit by Berenger : code formatting]